Chris enjoying the pictures. Most likely I will never run into one of these
oscillators. But it is nice to know that you have gone "where no man has
gone before". Star Trek? Not sure.
Regards
Paul
WB8TSL
On Wed, Nov 23, 2016 at 1:45 AM, Christopher Hoover <ch at murgatroid.com>
wrote:
> A Wiha nutdriver set later and I'm in:
>>https://goo.gl/photos/SDHtvgFmftQq6vYJA>> See the last two pictures.
>> I will disassemble the board stack and work out some schematics next.
>> Thanks everyone.
> -ch
> 73 de AI6KG
>> On Nov 20, 2016 5:19 AM, "J. L. Trantham" <jltran at att.net> wrote:
>> Christopher,
>> Enjoyed the pictures.
>> You might want to look at these items on theBay.
>> 381408412092
>> 311736541103
>> I've had the same issue and broke down and bought a set of these small nut
> drivers.
>> Good luck.
>> Joe
>> -----Original Message-----
> From: time-nuts [mailto:time-nuts-bounces at febo.com] On Behalf Of
> Christopher Hoover
> Sent: Saturday, November 19, 2016 11:45 PM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] Inside of FT1200-100
>> tl;dr: I've made some progress and have the1200 oscillator core out of the
> dewar:
>>https://goo.gl/photos/SDHtvgFmftQq6vYJA>>>> I got some 5 thou brass stock and worked it between the rubber sheet and
> the dewar.
>> That seemed to help but it was insufficient free things up -- I busted off
> the unused solder lug trying to pull the core out with it.
>> Having not a lot to lose, I took a chance that the screws going into the
> TO-23 went into threaded holes (rather than being clearance holes with nuts
> inside). This was indeed the case.
>> With two 6-32 threaded rods into the TO-23 threaded holes and and an
> appropriately machined piece of mild steel bar stock suspended across the
> case <https://goo.gl/photos/1pfiN2GX3WxYCSbg8>, I was able to easily get
> the oscillator core out of the dewar by evenly tightening the the nuts on
> the bar. Really easily -- I might have been able to pull it out by just
> pulling on the bar stock. I don't know if the shim stock shenanigans were
> even needed.
>> Despite running out the three sloted screws on the "top" around the
> circumference, I'm not into the inside yet. I don't have the right
> thin-walled socket to remove the nuts at the opposite end.
>> I found an epoxy covered hole on the top. It is/was under the green blob
> midway between 1 and 2 o'clock in this picture here <
>https://goo.gl/photos/> iHbSbqwBiKD7NRfJ6>.. There was something blue and
> at this point crumbly underneath it. Not sure yet what, if anything, is
> beyond all of that. I'm hoping for a trimmer cap. :-)
>> -- Christopher.
> 73 de AI6KG
>>>>> On Mon, Sep 26, 2016 at 9:24 PM, Chuck Harris <cfharris at erols.com> wrote:
>> > Back when I was going to work on mine, I was thinking of prying the
> > rubber away from the aluminum oven with something like a feeler gauge,
> > but also using some naptha (lighter fluid) to help release any
> > adhesive... I didn't get around to doing it, but that was the way I
> > was going to progress.
> >
> > -Chuck Harris
> >
> > Ed Palmer wrote:
> > >
> > >
> > > On 2016-09-26 10:00 AM, Christopher Hoover <ch at murgatroid.com> wrote:
> > >>> >
> > >>> >You might be able to slide something like a feeler guage down
> > >>> >between
> > the
> > >>> >oven and the rubber blanket to break the oscillator free. The
> > >>> >oven
> > on mine
> > >>> >is a plain metal cylinder. This way, the rubber sheet should
> > >>> >protect
> > the
> > >>> >Dewar from your feeler guage. On mine, the mounting bolts for
> > >>> >the
> > 2N3792
> > >>> >transistor both have ground lugs. I think I see them on yours.
> > >>> >You
> > could
> > >>> >hook something through the ground lugs and use that to pull the
> > oscillator
> > >>> >out of the rubber sheet and then remove the sheet later.
> > >>> >
> > >> Thanks Ed,
> > >>
> > >> I think the rubber sheet on mine is against metal. I haven't yet
> > >> seen
> > the
> > >> glass dewar.
> > >>
> > >> The adhesion is huge.
> > >>
> > >> Do you know if the holes opposite the 2N3792 are threaded? If they
> > are, I
> > >> might try running the screws out and using those holes with longer
> > screws
> > >> as my pull points. I can't pull on the lugs hard enough -- I've
> > tried.
> > >>
> > >> -christopher.
> > >> 73 de AI6KG
> > >
> > > Yes, you have seen the Dewar. The silvery ring that's outside the
> > rubber is the top
> > > of the Dewar. What you have to do is unstick and unfold the rubber
> > starting from the
> > > open area in the center. Work your way outward. The rubber is only
> > > 2
> > or 3 mm
> > > thick. Once you completely clear the rubber out of the way, you'll
> > > see
> > the edge of
> > > the oven. The TO-3 transistor is mounted on top of the oven assembly.
> > Once you can
> > > see the edge, you have to slide something like a long feeler gauge
> > > down
> > along the
> > > edge of the oven to break it free from the rubber. Work your way
> > > all
> > around the
> > > oven. It's about 85 mm long. It'll still be stuck on the bottom,
> > > but
> > you might be
> > > able to pull it free.
> > >
> > > When I took mine apart, I ended up tearing off all the rubber at the
> > > top
> > and then
> > > cutting out that ring of hard foam to get at the Dewar so I could
> > > smash
> > it more. I'm
> > > guessing you'd rather not do that! :) But sacrificing the rubber on
> > > the
> > top might be
> > > okay, if you have to.
> > >
> > > Sorry, but I don't know if the mounting holes for the transistor are
> > threaded or
> > > not. In any case, since the oven and Dewar are bonded to the
> > > rubber,
> > you're pulling
> > > on the Dewar when you pull on the oven. Not a good plan until you
> > > break
> > the oven
> > > free from the rubber. Those Dewars are built in a rather fragile
> > manner. Your
> > > typical home Thermos is much more robust.
> > >
> > > Ed
> > >
> > > _______________________________________________
> > > time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to
> > > https://www.febo.com/cgi-bin/> > mailman/listinfo/time-nuts
> > > and follow the instructions there.
> > >
> > _______________________________________________
> > time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to
> > https://www.febo.com/cgi-bin/ mailman/listinfo/time-nuts and follow
> > the instructions there.
> >
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to
>https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> and follow the instructions there.
>> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com> To unsubscribe, go to https://www.febo.com/cgi-bin/> mailman/listinfo/time-nuts
> and follow the instructions there.
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com> To unsubscribe, go to https://www.febo.com/cgi-bin/> mailman/listinfo/time-nuts
> and follow the instructions there.
>